1. Field of the Invention
The invention relates to a circuit arrangement for use with a trackbound propulsion vehicle. More particularly, it relates to a traveling-field winding which is installed alongside the vehicle roadbed and forms the stator of a linear synchronous motor whose exciter is disposed as a co-movable translator on the vehicle itself.
Linear motors merit preferential consideration as drive systems for trackbound propulsion vehicles, as for example, cabin cars in local traffic and high-speed trains, as well as for magnetic suspension vehicles, such as high-efficiency, high-speed trains in the speed range of up to 500 km/h. Among the various variants of this type of motor, the linear synchronous motor is particularly noted for its good efficiency and high power factor.
More specifically, the stator of such a linear synchronous motor may typically be designed as a traveling-field winding which is installed alongside the vehicle roadbed and which is generally polyphase in nature (see, for example, Archiv fur Elektrotechnik, vol. 55, No. 1 (1972) p. 13/20). The exciter of the motor, on the other hand, is generally disposed on the propulsion vehicle itself as a co-movable exciter (translator) and can be either a dc-fed exciter winding which may extend over the entire length of the vehicle, or a permanent magnet. Because of the extraordinary length of the motor stator, such a motor is also called a synchronous long-stator motor.
In response to an applied voltage and frequency, the traveling-field winding of the motor generates a traveling-field which runs in the longitudinal direction of the roadbed and drives the propulsion vehicle. In order for the linear synchronous motor to properly accelerate such a trackbound propulsion vehicle from standstill to a specified maximum speed, the stator is provided, in the area of each vehicle stopping station, with an acceleration span which has a predetermined number of feeding sections disposed one behind the other in the travel direction and which are referred to as the acceleration sections of the stator. Each acceleration section is supplied by a separate converter with a variable ac voltage and frequency. Advantageously, these acceleration sections are operated at a high current density so as to obtain large accelerations of about 0.1 g (g = gravity acceleration). A corresponding procedure is followed to decelerate the propulsion vehicle from its maximum speed to a stop.
It is an object of the present invention to design the above-mentioned type of propulsion vehicle circuit arrangement so as to make it possible to accelerate or decelerate the propulsion vehicle at a high acceleration or deceleration rate and with good matching of the power fed into or supplied by the respective acceleration sections to the rated capacity of their respective converters.